Odor Footprint Tool Progress: Regional Output Resources

University of Nebraska 2006 Swine Day Report. This article highlights practical applications for resources being developed using the Odor Footprint Tool and the effects of differing regional weather patterns on needed setbacks by describing resources created for the regions surrounding Norfolk and Lincoln, Neb. The Odor Footprint Tool is being developed to help people assess the odor impact of new and expanded animal production facilities on the surrounding areas and use science- based information to establish minimum setback distances. Progress continues to be made toward development of a system that can be used in the field to develop site-specific odor footprints. As an intermediate step in this process, regional sets of Odor Footprint Tool resources are being developed for more general use. Odor roses, directional setback distance curves, and odor footprints are being produced for six regions in Nebraska. Odor roses provide a descriptivepictureof the directionality of odor annoyancewithin a region, independent of the type or size of livestock facility involved. Odor roses are well suited for general planning and educational purposes where mainly the directional fate of odor emissions is desired. Directional setback distance curves facilitate determining minimum setback distances in four 90-degree sectors around a site, based upon the total odor emission rate of the site. The total emission rate dependson the size and type of livestock housing and/or manure storage facilities involved, and whether any odor control technologies are implemented. Directional setback distance curves are especially useful when principal setback distances are desired, and when a number of preliminary comparisons are to be made. Odor footprints show curves similar to contour lines representing the locations around a livestock site that have common expected frequencies of odor annoyance. Odor footprints correspond to specific scenarios (having specific total odor emission rates) and are useful for visualizing the projected odor impact of an operation on the surrounding area. As livestock producers, their service providers, and regulatory officials begin to use these resources, they should be better able to make reasonable decisions regarding the odor impact of livestock operations on surrounding neighbors and rural communities. Odor impact at a given location is presented in terms of the likelihood that odor will exist at annoying intensity levels. Producers can use the frequency of annoyance information and the corresponding percentages of time that odor annoyance is not expected (odor annoyance-free frequencies) to help evaluate their risk of offending neighbors and to determine which neighbors are at greatest risk. This information will be helpful when evaluating sites and in determining the benefit of implementing proven odor control technologies. Also, regulatory officials will have access to science- based information that can form the basis of reasonable discussions at public hearings and be considered in decision processes for applications to build livestock facilities.